The fat pen is fairly useful in this app since when active it doesn't let you go outside the lines. However, you only seem to get to use it when the shape isn't divided up into sections.
I've used other apps (a branded Crayola one on Nintendo DS springs to mind) where it remembers where you put the stylus down and keeps you within the lines of that section until you lift it from the page. Worked quite well and I think it'd be a good fit for this app.
I've used other apps (a branded Crayola one on Nintendo DS springs to mind) where it remembers where you put the stylus down and keeps you within the lines of that section until you lift it from the page. Worked quite well and I think it'd be a good fit for this app.